More than 1,500 manufactured gas plants operated throughout the U.S. from the mid-1800s through the mid-1900s to provide gas for lighting, heating, cooking and other purposes. These plants used a variety of processes to make gas by heating coal and/or oil. The by-product from this method was known as coal tar. Very often, these coal tars were left behind in subsurface structures and soils when the plants were closed.

In 1996, O&R and the New York State Department of Environmental Conservation (NYSDEC) signed an agreement in which the utility undertook an examination of its seven former manufactured gas plant sites in Orange and Rockland counties to determine whether any coal tar or other residue from the obsolete gas manufacturing process remains on the sites.

Haverstraw — Maple Avenue

O&R successfully completed the excavation work in June 2005 on Phase II of its project to excavate coal tar-impacted soil from the area adjacent to the site of a predecessor company's manufactured gas plant that closed its doors over 100 years ago on Maple Avenue in the Village of Haverstraw.

Now, final reports are being prepared for regulators who are expected to sign off on the project's completion sometime before next spring.

The principal excavation in Phase I of this project, which began in November 2002 and was completed in December 2003, was approved as completed by NYSDEC/NYSDOH in March 2005. Phase I included excavation at 93B Maple Avenue as well as excavation of portions of 87, 91 and 95 Maple Avenue.

Phase II of the project proceeded much as the first phase did, and encompassed properties located at 99, 103 and 104 Maple Ave. Test drilling at 99, 103 and 104 Maple Ave. had shown the presence of coal tar-impacted soil of sufficient quantity to require a cleanup.

Coal tar contains organic compounds such as benzene, toluene, xylene and napthalene. In the case of 99, 103 and 104 Maple Ave., the coal tar was buried approximately 10 to 20 feet beneath the ground where there was little possibility of anyone coming in contact with the coal tar and/or impacted soils. In addition, since homes and businesses in the area of this site are served by public water, exposure to site-related contaminants in drinking water was not a concern.

Since one of the most effective ways to "clean up" these contaminants was to remove the contaminated soil and replace it with clean fill, this is the remedy that was selected for these properties. This will ensure that any future activities on the site, if any, can go forward unimpeded and unrestricted. The impacted excavated soil, which was replaced with clean fill, was trucked to a licensed disposal site.

All construction means, methods, sequencing and staging were arranged to protect the residences and their occupants and provide safe means of access and egress to Maple Avenue at all times.

There was a small area of impacted soil remaining under the 93B Maple Avenue building that could not be excavated. Therefore, in situ treatment of these soils with a chemical oxidant was included in the Phase II work. The results of this treatment are still under review by NYSDEC/NYSDOH. A final evaluation of the treatment's effectiveness will be included in the Record of Decision that will be issued for Phase II.

Still on the drawing board as testing continues to evaluate the situation, is another remediation project slated to be conducted further down Maple Ave. at a site where O&R currently operates a gas regulator station. This site is referred to as the Clove & Maple site and was the home of a manufactured gas plant many years ago as well.

Copies of all previous Work Plans and Reports are available at Haverstraw's King's Daughters Library. Prior to additional work being conducted, a public information meeting will be scheduled. Spanish translation services are available for those needing them to review any of the existing documents and/or any new work plans. The New York State Department of Health (NYSDOH) will be monitoring O&R's work as will the New York State Department of Environmental Conservation (NYSDEC).

For further information from O&R, please call Neil Winter at 845-577-2147.

Nyack — Gedney Street

O&R, the New York State Department of Environmental Conservation (NYSDEC), and the New York State Department of Health (NYSDOH) are now involved in another manufactured gas plant cleanup project — this one on Gedney Street in the Village of Nyack.

The next phase of that cleanup project — which is to begin in late autumn or early winter this year — will involve the excavation of soils from the upper terrace of the vacant lot currently owned by Presidential Life Insurance Co. In addition to the principal excavation, this next phase of work also will include solidification of soils located in the lower parking lot of the adjacent Hudson Vista property.

O&R is presently treating those areas on the site where coal tar is present in the bedrock by pumping hydrogen peroxide with a catalyst into on-site wells. Coal tars that are fully oxidized are converted to water and carbon dioxide. Any coal tars that are not fully oxidized will be made more stable and less mobile.

When the site excavation begins, the work will take place under a large tent-like structure with an air-handling system and carbon filters. This temporary structure will control vapors and dust generated during the excavation of soil that is contaminated with coal tar. The effectiveness of the structure will be verified by real-time air monitoring conducted 24-hours a day, seven days per week during the project. These precautions will also minimize the potential for odors from the excavation.

Soil will be excavated down to bedrock at a depth of 10 to 15 feet. The excavated material will be loaded into tractor-trailers, which will transport the material to licensed disposal sites.

Historical records indicate that this manufactured gas plant operated from 1852 until 1965. It is believed that gas was made from coal and oil from 1852 until 1889. From 1890 until 1938, the plant used both coal and oil as feedstock for the carbureted water gas process. From 1938 until 1965, the site was used as an oil gas facility only during times of peak demand, a practice known as "peak shaving".

The Excavation Work Plan and other site-related documents are available for review at the following locations: